Linear style battery chargers are well-known in the art. Recently, multi-frequency and high-frequency battery chargers have entered the market and proven effective at providing charge energy to various types of batteries at a much increased efficiency. However, both types of battery chargers suffer from several significant drawbacks.
Generally, a large transformer provides more current than a smaller transformer, but also experiences greater electrical losses as it operates. Relatively large transformers are needed in order to provide the high current necessary to charge a battery. However, when a battery is fully charged, float charging or trickle charging the battery to maintain its charge only requires a relatively low current. Battery chargers which use only one transformer must select a large transformer in order to provide the high current necessary, but must endure the high losses of the large transformer even when providing only a maintenance charge. Using multiple transformers does little to remedy this if all of the transformers remain active and connected, as transformers experience electrical power loss even when they are not providing current.